Recording medium playback device and recording medium playback method

Abstract

There is provided a recording medium playback device that includes a first binarization portion that binarizes, by a PRML method, a signal that is read from a recording medium, a second binarization portion that binarizes the signal based on a magnitude relationship to a specified threshold value, a first frame synchronization signal detection portion that detects a synchronization pattern in a first binarized data string that is produced by the first binarization portion, and a second frame synchronization signal detection portion that detects a synchronization pattern in a second binarized data string that is produced by the second binarization portion. If the synchronization pattern is not detected by the first frame synchronization signal detection portion, a signal that is derived from the synchronization pattern that is detected by the second frame synchronization signal detection portion is used as the frame synchronization signal.

1. A recording medium playback device, comprising:
 a first binarization portion that, using a partial response maximum likelihood decoding processing, binarizes a signal that is read from data that is recorded in a recording medium; 
 a second binarization portion that binarizes the signal based on a magnitude relationship to a specified threshold value; and 
 a frame synchronization signal detection portion that detects a frame synchronization signal in data that have been processed by the first binarization portion and the second binarization portion, the frame synchronization signal detection portion including 
 a first frame synchronization signal detection portion that detects a synchronization pattern in a first binarized data string that is produced by the first binarization portion, and determines by a pattern matching whether the first binarized data string is the synchronization pattern and whether the first binarized data string is a detection pattern, and 
 a second frame synchronization signal detection portion that detects a synchronization pattern in a second binarized data string that is produced by the second binarization portion, 
 wherein if the synchronization pattern is not detected by the first frame synchronization signal detection portion, a signal that is derived from the synchronization pattern that is detected by the second frame synchronization signal detection portion is used as the frame synchronization signal. 
 
     
     
       2. The recording medium playback device according to  claim 1 ,
 the first frame synchronization signal detection portion determines by a pattern matching whether the first binarized data string, minus a specified bit, is the synchronization pattern and whether the first binarized data string, minus the specified bit, is a detection pattern, and 
 when the synchronization pattern is not detected in the first binarized data string, minus the specified bit, and the detection pattern is detected, 
 the signal that is derived from the synchronization pattern that is detected by the second frame synchronization signal detection portion is used as the frame synchronization signal. 
 
     
     
       3. The recording medium playback device according to  claim 1 ,
 wherein the second binarization portion performs a high frequency emphasis processing of the signal that is read from the recording medium before binarizing the signal. 
 
     
     
       4. A recording medium playback device, comprising:
 a first binarization portion that, using a partial response maximum likelihood decoding processing, binarizes a signal that is read from data that is recorded in a recording medium; and 
 a second binarization portion that binarizes the signal based on a magnitude relationship to a specified threshold value, 
 a frame synchronization signal detection portion for detecting a binarized data string that is produced by the second binarization portion, by determining a pattern match to detect whether the binarized data string is the synchronization pattern and whether the binarized data string is a detection pattern, and a signal that is derived from the synchronization pattern is used as a frame synchronization signal, and 
 the data that is processed by the first binarization portion is used only for playback of the data. 
 
     
     
       5. A recording medium playback method, comprising the steps of:
 binarizing, using a partial response maximum likelihood decoding processing, a signal that is read from data that is recorded in a recording medium; 
 binarizing the signal based on a magnitude relationship to a specified threshold value; and 
 detecting a frame synchronization signal in data that have been processed by the binarizing of the signal using the partial response maximum likelihood decoding processing and the binarizing of the signal based on the magnitude relationship to the specified threshold value, the detecting of the frame synchronization signal including 
 detecting a synchronization pattern in a first binarized data string that is produced by the binarizing of the signal using the partial response maximum likelihood decoding processing, by determining a pattern match indicating whether the first binarized data string is the synchronization pattern and whether the first binarized data string is a detection pattern, and 
 detecting a synchronization pattern in a second binarized data string that is produced by the binarizing of the signal based on the magnitude relationship to the specified threshold value, 
 wherein if the synchronization pattern is not detected in the first binarized data string, a signal that is derived from the synchronization pattern that is detected in the second binarized data string is used as the frame synchronization signal. 
 
     
     
       6. The recording medium playback method according to  claim 5 , wherein
 the detecting of the synchronization pattern in the first binarized data string determines by a pattern matching whether the first binarized data string, minus a specified bit, is the synchronization pattern and whether the first binarized data string, minus the specified bit, is a detection pattern, and 
 when the synchronization pattern is not detected in the first binarized data string, minus the specified bit, and the detection pattern is detected, 
 the signal that is derived from the synchronization pattern that is detected in the second binarized data string is used as the frame synchronization signal. 
 
     
     
       7. The recording medium playback method according to  claim 5 ,
 wherein a high frequency emphasis processing of the signal that is read from the recording medium is performed before the binarizing of the signal based on the magnitude relationship to the specified threshold value. 
 
     
     
       8. A recording medium playback method, comprising the steps of:
 binarizing, using a partial response maximum likelihood decoding processing, a signal that is read from data that is recorded in a recording medium; and 
 binarizing the signal based on a magnitude relationship to a specified threshold value, 
 wherein a synchronization pattern is detected in a binarized data string that is produced by the binarizing of the signal based on the magnitude relationship to the specified threshold value, and a signal that is derived from the synchronization pattern is used as a frame synchronization signal, by determining a pattern match indicating whether the binarized data string is the synchronization pattern and whether the binarized data string is a detection pattern, and 
 the data that is processed by the binarizing of the signal using the partial response maximum likelihood decoding processing is used only for playback of the data.